Sammanfattning

Human introductions have resulted in earthworms establishing in the Arctic, species known to cause cascading ecosystem change. However, few quantitative outdoor experiments have been performed that describe how these soil modifying earthworms are reshaping structures in tundra soils. In this study, we used three-dimensional (3-D) X-ray images of soil cores (approximately 10 cm diameter, 20 cm height, N = 48) to assess how earthworms (Aporrectodea sp. and Lumbricus sp.) affect soil structure and macropore networks in an outdoor mesocosm experiment that lasted four summers. Effects were assessed in both shrub-dominated (heath) and herb-dominated (meadow) tundra. Earthworms almost doubled the macroporosity in meadow soils and tripled macroporosity in heath. Interestingly, the fractal dimension of macropores decreased in response to earthworm burrowing in both systems, indicating that the presence of earthworms reduced the geometric complexity in comparison to other pore-generating processes active in the tundra. Observed effects on soil structure occurred along with a dramatically reduced soil moisture content, which was observed the first winter after earthworm introduction in the meadow. Our findings suggest that predictions of future changes in vegetation and soil carbon pools in the Arctic should include major impacts on soil properties that earthworms induce.

Nyckelord

3D; Bioturbation; Soil-mixing; Abisko; Meadow; Heath; Long-term

Publicerad i

Science of the Total Environment
2023, Volym: 859, nummer: Part 2, artikelnummer: 160125

SLU författare

• Krab, Eveline

  • Institutionen för mark och miljö, Sveriges lantbruksuniversitet
    
  • Umeå Universitet

• Larsbo, Mats

  • Institutionen för mark och miljö, Sveriges lantbruksuniversitet
    

• Koestel, Johannes

  • Institutionen för mark och miljö, Sveriges lantbruksuniversitet
    
  • Agroscope

Globala målen

Skydda, återställa och främja ett hållbart nyttjande av landbaserade ekosystem, hållbart bruka skogar, bekämpa ökenspridning, hejda och vrida tillbaka markförstöringen samt hejda förlusten av biologisk mångfald


UKÄ forskningsämne

Markvetenskap
Miljövetenskap


Publikationens identifierare

DOI: https://doi.org/10.1016/j.scitotenv.2022.160125

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/120499